Results 1 to 10 of about 283,464 (299)

X-ray active galactic nuclei in the core of the Perseus cluster [PDF]

Monthly Notices of the Royal Astronomical Society, 2007
We present a study of the X-ray emission from the nuclei of galaxies observed in the core of the Perseus cluster in a deep exposure with Chandra. Point sources are found coincident with the nuclei of 13 early-type galaxies, as well as the central galaxy NGC1275. This corresponds to all galaxies brighter than M_B = -18 in the Chandra field. All of these
S. Santra, J. S. Sanders, A. C. Fabian
semanticscholar   +7 more sources

X-ray Eclipses of Active Galactic Nuclei [PDF]

The Astrophysical Journal, 2017
X-ray variation is a ubiquitous feature of active galactic nuclei (AGNs), however, its origin is not well understood. In this paper, we show that the X-ray flux variations in some AGNs, and correspondingly the power spectral densities (PSDs) of the ...
Lu, Youjun, Yu, Qingjuan, Zhang, Fupeng
core   +4 more sources

The Correlation between X-ray spectral slope and FeKalpha line energy in radio-quiet active galactic nuclei [PDF]

Astrophys.J. 581 (2002) L71-L76, 2002
A significant correlation between FeKalpha line energy and X-ray spectral slope has been discovered among radio-quiet active galactic nuclei. The ionization stage of the bulk of the FeKalpha emitting material is not the same in all active galactic nuclei and is related to the shape of the X-ray continua.
Arnaud K. A., Boller T., Brandt W. N., Fabian A. C., George I. M., Grupe D., Guainazzi M., Guilbert P. W., Gulab Chand Dewangan, Koenig M., Mineo T., Pounds K. A., Reynolds C. S., Winkler H., Wisotzki L.   +14 more
arxiv   +3 more sources

X-ray Absorption and Reflection in Active Galactic Nuclei [PDF]

The Astronomy and Astrophysics Review, 2009
X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of material to ...
A Abrassart, A Celotti, A Laor, A Lawrence, A Lawrence, A Marconi, A Marconi, A Markowitz, A Merloni, A Orr, A Ptak, A Soltan, A Wandel, A Wandel, AA Zdziarski, AC Fabian, AC Fabian, AC Fabian, AC Fabian, AC Fabian, AC Gonçalves, AJ Blustin, AJ Blustin, AJ Young, AK Turner, AK Turner, AL Longinotti, AL Longinotti, AP Lightman, AR Green, AR King, AW Graham, B Czerny, B Czerny, B Czerny, B Ercolano, B McKernan, B McKernan, B McKernan, BJ Boyle, BJ Wilkes, BM Peterson, BM Peterson, BM Peterson, C Done, C Matsumoto, C Otani, CA Onken, CB Tarter, CM Gaskell, CM Urry, CS Bowyer, CS Reynolds, CS Reynolds, CS Reynolds, CS Reynolds, CS Reynolds, CS Reynolds, D Chelouche, D Porquet, D Proga, D Proga, D Proga, DA Leahy, DE Osterbrock, DJ Axon, DM Crenshaw, DR Ballantyne, E Behar, F Fiore, F Haardt, F Haardt, F Haardt, F Nicastro, F Panessa, G Branduardi-Raymont, G Chartas, G Chartas, G Chartas, G Ghisellini, G Matt, G Matt, G Matt, G Matt, G Miniutti, G Miniutti, G Miniutti, G Ponti, G Risaliti, G Risaliti, G Zamorani, GA Reichert, GJ Ferland, GJ Ferland, GJ Ferland, GT Richards, H Inoue, H Netzer, H Netzer, H Netzer, H Netzer, HC Pan, IE Papadakis, IM George, IM George, J Crummy, J Kormendy, J Larsson, J Magorrian, J Reeves, J Tueller, J Wilms, JC Lee, JC Lee, JH Krolik, JH Krolik, JH Krolik, JH Woo, JM Wang, JN Reeves, JN Reeves, JN Reeves, JN Reeves, JP Halpern, JS Kaastra, JS Kaastra, JW den Herder, JW Sulentic, K Gebhardt, K Iwasawa, K Iwasawa, K Koyama, K Mitsuda, K Nandra, K Nandra, K Nandra, K Nandra, K Nandra, K Nandra, K Nandra, K Nandra, KA Arnaud, KA Pounds, KA Pounds, KA Pounds, KA Pounds, KA Pounds, KA Pounds, KA Pounds, KA Pounds, KA Weaver, KC Steenbrugge, KK Ghosh, KL Page, KM Leighly, L Bassani, L Chevallier, L Ferrarese, L Miller, L Miller, L Miller, L Piro, L Piro, L Piro, L Titarchuk, L. Miller, LC Ho, LG Titarchuk, LW Brenneman, M Camenzind, M Dadina, M Dadina, M Dadina, M Dovčiak, M Dovčiak, M Elvis, M Gierliński, M Guainazzi, M Guainazzi, M Matsuoka, M Matsuoka, M Middleton, M Sako, M Ward, MA Abramowicz, MA Abramowicz, MA Bautista, MA Sobolewska, MJ Rees, MT Ceballos, N Marshall, N Murray, NI Shakura, NJ Schurch, NJ Schurch, P Gondoin, P Magdziarz, P Padovani, P Palmeri, PO Petrucci, PT Życki, PW Guilbert, Q Yu, R Antonucci, R Giacconi, R Morales, R Narayan, R Walter, RAN Smith, RF Mushotzky, RF Mushotzky, RJ Weymann, RR Ross, RR Ross, RS Warwick, RW Goosmann, S Bianchi, S Bianchi, S Bianchi, S Bianchi, S Bianchi, S Collin, S Kaspi, S Kaspi, S Kaspi, S Mineshige, S Miyoshi, S Nayakshin, S Nayakshin, S Puccetti, S Tremaine, S Vaughan, SA Sim, SB Kraemer, SS Różańska Holt, T Boller, T Boller, T Kallman, T Mihara, T Takahashi, T Yaqoob, T Yaqoob, T Yaqoob, T Yaqoob, T Yaqoob, T Yaqoob, T. J. Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TJ Turner, TM Heckman, TM Heckman, TR Kallman, V Beckmann, V Braito, V Karas, W Bian, W Tucker, WN Brandt, XB Wu, Y Krongold, Y Krongold, Y Tanaka, Y Tanaka   +272 more
core   +5 more sources

X-ray absorption in Active Galactic Nuclei [PDF]

arXiv, 2007
We review some of the main physical and statistical properties of the X-ray absorber in AGNs. In particular, we review the distribution of the absorbing column density inferred from X-ray observations of various AGN samples. We discuss the location of the X-ray absorber and the relation with the dust absorption at optical and infrared wavelengths ...
Maiolino, R., Risaliti, G.
arxiv   +3 more sources

[C II] emission from galactic nuclei in the presence of X-rays [PDF]

A&A 580, A5 (2015), 2015
The luminosity of [C II] is used to probe the star formation rate in galaxies, but the correlation breaks down in some active galactic nuclei (AGNs). Models of the [C II] emission from galactic nuclei do not include the influence of X-rays on the carbon ionization balance, which may be a factor in reducing the [C II] luminosity. We calculate the [C II]
Langer, William D., Pineda, Jorge L.
arxiv   +3 more sources

Radiation pressure acceleration by X-rays in active galactic nuclei [PDF]

Monthly Notices of the Royal Astronomical Society, 2001
We present calculations of the dynamics of highly ionized gas clouds that are confined by external pressure, and are ionized by AGN continuum. We focus on the gas that is seen in absorption in the X-ray spectrum of many AGN and show that such gas can reach hydrostatic equilibrium under various conditions. The principal conclusion is that the clouds can
Doron Chelouche, H. Netzer
openalex   +5 more sources

Soft X-ray active galactic nuclei

The Astrophysical Journal, 1984
The discovery of 10 active galactic nuclei (AGNs) based upon optical observations of Einstein Observatory X-ray sources is reported. The new objects are optically similar to AGNs that have been identified by others with this technique. One notable exception, the quasar E1821 + 643, is associated with a previously unidentified X-ray source detected with
F. E. Marshall, S. H. Pravdo
openaire   +3 more sources

Local supermassive black holes, relics of active galactic nuclei and the X-ray background [PDF]

, 2004
We quantify the importance of mass accretion during AGN phases in the growth of supermassive black holes (BH) by comparing the mass function of black holes in the local universe with that expected from AGN relics, which are black holes grown entirely ...
A. Marconi, G. Risaliti, R. Gilli, L. K. Hunt, R. Maiolino, M. Salvati   +5 more
openalex   +3 more sources

Sources of X-rays from galaxies [PDF]

, 2011
Galactic X-ray emission is a manifestation of various high-energy phenomena and processes. The brightest X-ray sources are typically accretion-powered objects: active galactic nuclei and low- or high-mass X-ray binaries. Such objects with X-ray luminosities of > 10^{37} ergs/s can now be detected individually in nearby galaxies.
Liu, Persic, Porquet, Q. Daniel Wang, Revnivtsev, Revnivtsev, Sazonov, Tüllmann, Weźgowiec, Yuan, Zhang   +10 more
arxiv   +4 more sources